CN107922794A - Bonding sheet - Google Patents

Abstract

The present invention provides a kind of bonding sheet, it is the bonding sheet used when the semiconductor element on to bonding sheet seals, the bonding sheet (10) possesses base material (11) and adhesive phase (12), and the value tried to achieve in the chip pull test that described adhesive layer (12) carries out silicon under 100 DEG C of gaseous environment is more than 3.0N/ chip.

Description

adhesive sheet

technical field

The present invention relates to an adhesive sheet.

Background technique

In recent years, among mounting technologies, a chip size package (Chip Size Package; CSP) technology has attracted attention. Among these technologies, packaging in the form of chips without using a substrate, typified by wafer level packaging (WLP), is attracting attention in terms of miniaturization and high integration.

In such a WLP manufacturing method, conventionally, it was necessary to fix the chip fixed on the substrate to another support. Therefore, for example, Patent Document 1 describes an adhesive tape used for adhering when resin-sealing a substrate-less semiconductor chip that does not use a metal lead frame. Patent Document 1 describes an adhesive tape in which an adhesive layer having an elastic modulus at 180°C of 1.0×10 ⁵ Pa or higher is provided on one or both sides of a substrate layer having a glass transition temperature of more than 180°C. .

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2012-062372

Contents of the invention

The problem to be solved by the invention

However, with the adhesive tape described in Patent Document 1, it is not always possible to sufficiently prevent movement of the semiconductor element when sealing the semiconductor element.

An object of the present invention is to provide an adhesive sheet capable of preventing a semiconductor element from moving and being displaced when sealing the semiconductor element on the adhesive sheet.

Solution to the problem

According to one aspect of the present invention, there is provided a PSA sheet used for sealing a semiconductor element on a PSA sheet, the PSA sheet having a base material and an PSA layer, and having a temperature of 100° C. The value obtained in the chip tensile test of the adhesive layer against silicon in a gas environment is 3.0 N/chip or more.

In the pressure-sensitive adhesive sheet according to one embodiment of the present invention, it is preferable that the base material has a storage modulus at 100°C of 1×10 ⁷ Pa or more.

In the PSA sheet according to one aspect of the present invention, it is preferable that the PSA layer contains an acrylic PSA composition or a silicone PSA composition.

In the PSA sheet according to one embodiment of the present invention, it is preferable that the acrylic PSA composition contains an acrylic copolymer containing 2-ethylhexyl acrylate as a main monomer.

In the pressure-sensitive adhesive sheet according to one embodiment of the present invention, it is preferable that the silicone-based pressure-sensitive adhesive composition contains an addition-polymerized silicone resin.

According to the present invention, it is possible to provide an adhesive sheet capable of preventing the semiconductor element from moving and being displaced when sealing the semiconductor element on the adhesive sheet.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a PSA sheet according to an embodiment of the present invention.

2A is a diagram illustrating a part of the manufacturing process of a semiconductor device using the adhesive sheet according to the embodiment of the present invention.

2B is a diagram illustrating a part of the manufacturing process of the semiconductor device using the adhesive sheet according to the embodiment of the present invention.

2C is a diagram illustrating a part of the manufacturing process of the semiconductor device using the adhesive sheet according to the embodiment of the present invention.

2D is a diagram illustrating a part of the manufacturing process of the semiconductor device using the adhesive sheet according to the embodiment of the present invention.

2E is a diagram illustrating a part of the manufacturing process of the semiconductor device using the adhesive sheet according to the embodiment of the present invention.

FIG. 3A is a schematic diagram for explaining a method of a chip pull test.

FIG. 3B is a schematic diagram for explaining the method of the chip pull test.

FIG. 3C is a schematic diagram for explaining the method of the chip pull test.

FIG. 3D is a schematic diagram for explaining a method of a chip pull test.

FIG. 3E is a schematic diagram for explaining the method of the chip pull test.

FIG. 3F is a schematic diagram for explaining the method of the chip pull test.

FIG. 3G is a schematic diagram for explaining a method of a chip pull test.

FIG. 3H is a schematic diagram for explaining the method of the chip pull test.

Symbol Description

10…adhesive sheet

11...Substrate

12...Adhesive layer

Detailed ways

[implementation mode]

(adhesive sheet)

FIG. 1 shows a schematic cross-sectional view of an adhesive sheet 10 according to this embodiment.

The adhesive sheet 10 has a base material 11 and an adhesive layer 12 . As shown in FIG. 1 , a release sheet RL is laminated on the pressure-sensitive adhesive layer 12 .

The base material 11 has the 1st base material surface 11a, and the 2nd base material surface 11b opposite to the 1st base material surface 11a. The shape of the pressure-sensitive adhesive sheet 10 may be, for example, any shape such as a sheet shape, a tape shape, or a label shape.

(Substrate)

The base material 11 is a member that supports the adhesive layer 12 .

As the base material 11, for example, a sheet material such as a synthetic resin film or the like can be used. Examples of synthetic resin films include polyethylene films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyterephthalmic Ethylene formate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, ionomer resin film, ethylene-(formyl base) acrylic copolymer film, ethylene-(meth)acrylate copolymer film, polystyrene film, polycarbonate film, and polyimide film. Moreover, as the base material 11, these crosslinked films, a laminated film, etc. are mentioned.

The base material 11 preferably contains a polyester resin, and is more preferably made of a material mainly composed of a polyester resin. In this specification, a material mainly composed of a polyester resin means that the mass of the polyester resin accounts for 50% by mass or more of the total mass of the materials constituting the base material. As the polyester resin, for example, preferably selected from polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polybutylene naphthalate resin, Alcohol ester resins and arbitrary resins among copolymer resins of these resins are more preferably polyethylene terephthalate resins.

As the base material 11, polyethylene terephthalate film and polyethylene naphthalate are preferable, and polyethylene terephthalate film is more preferable. The oligomers contained in the polyester film are derived from polyester-forming monomers, dimers, trimers, and the like.

From the viewpoint of dimensional stability during processing, the lower limit of the storage modulus at 100° C. of the substrate 11 is preferably 1×10 ⁷ Pa or more, more preferably 1×10 ⁸ Pa or more. From the viewpoint of processing suitability, the upper limit of the storage modulus at 100° C. of the substrate 11 is preferably 1×10 ¹² Pa or less. In addition, in this specification, a storage elastic modulus is a value measured by the torsional shear method at a frequency of 1 Hz using a dynamic viscoelasticity measuring device. The substrate to be measured was cut into a width of 5 mm and a length of 20 mm, and the storage energy viscoelasticity at 100° C. was measured using a viscoelasticity measuring device (manufactured by TA Instruments, DMAQ800) at a frequency of 11 Hz and in a tensile mode.

In order to improve the adhesiveness with the pressure-sensitive adhesive layer 12 to the 1st base material surface 11a, you may give at least any one surface treatment among primer treatment, corona treatment, plasma treatment, etc. Adhesive treatment may be performed by applying an adhesive to the first base material surface 11 a of the base material 11 . Examples of the adhesive used for the bonding treatment of the substrate include acrylic, rubber, silicone, and urethane adhesives.

The thickness of the substrate 11 is preferably not less than 10 μm and not more than 500 μm, more preferably not less than 15 μm and not more than 300 μm, and still more preferably not less than 20 μm and not more than 250 μm.

(adhesive layer)

In the present embodiment, the value obtained in the chip pull test of the adhesive layer 12 against silicon in an atmosphere of 100° C. needs to be 3.0 N/chip or more. When the value obtained in the chip pull test is 3.0 N/chip or more, when sealing the semiconductor element on the adhesive sheet, it is possible to prevent the semiconductor element from moving and misaligning (hereinafter sometimes referred to as chip shift). The reason for this is not clear, but it is presumed to be the following mechanism. That is, it can be presumed that the chip shift is not caused by the lateral sliding of the semiconductor element on the adhesive layer 12, but that the semiconductor element is peeled off from the adhesive layer 12, moved, and bonded again. Therefore, the larger the value obtained in the chip pull test, the more difficult it is for the semiconductor element to be peeled off from the adhesive layer 12 . Therefore, it is presumed that there is a correlation between the value obtained in the chip pull test and the chip offset.

In addition, from the viewpoint of more reliably preventing positional displacement of the semiconductor element, the value obtained in the chip pull test is preferably 4.0 N/chip or more, more preferably 5.0 N/chip or more and 15 N/chip or less. If the value obtained in the chip pull test is less than 3.0N/chip, chip shift may occur, and if it exceeds 15N/chip, the circuit surface of the semiconductor element may be damaged when the semiconductor element is peeled off from the adhesive sheet.

The value obtained in the chip pull test of the adhesive layer 12 against silicon in an atmosphere of 100° C. can be measured by the method described in Examples described later.

In addition, as a method of adjusting the value calculated|required by this chip pull test, the following method is mentioned. For example, the value obtained in the chip pull test is adjusted by changing the composition of the adhesive composition used for the adhesive layer 12 .

The adhesive layer 12 of this embodiment contains an adhesive composition. The adhesive contained in the adhesive composition is not particularly limited, and various adhesives can be applied to the adhesive layer 12 . Examples of the adhesive contained in the adhesive layer 12 include rubber-based, acrylic-based, silicone-based, polyester-based, and urethane-based. It should be noted that the type of adhesive can be selected in consideration of the application, the type of adherend to be pasted, and the like. The adhesive layer 12 preferably contains an acrylic adhesive composition or a silicone adhesive composition.

·Acrylic adhesive composition

When the pressure-sensitive adhesive layer 12 contains an acrylic pressure-sensitive adhesive composition, the acrylic pressure-sensitive adhesive composition preferably contains an acrylic copolymer containing 2-ethylhexyl acrylate as a main monomer.

In addition, when the pressure-sensitive adhesive layer 12 contains an acrylic pressure-sensitive adhesive composition, it is preferable to contain an acrylic copolymer and an adhesion assistant. The acrylic copolymer is preferably a copolymer containing 2-ethylhexyl acrylate as a main monomer. The adhesion aid preferably contains a rubber-like material having a reactive group as a main component.

In this specification, using 2-ethylhexyl acrylate as the main monomer means that the mass of the copolymer component derived from 2-ethylhexyl acrylate accounts for 50% by mass of the total mass of the acrylic copolymer %above. In the present embodiment, the ratio of the copolymer component derived from 2-ethylhexyl acrylate in the acrylic copolymer is preferably 50% by mass to 95% by mass, more preferably 60% by mass to 95% by mass, More preferably, it is 80 mass % or more and 95 mass % or less, More preferably, it is 85 mass % or more and 93 mass % or less. If the proportion of the copolymer component derived from 2-ethylhexyl acrylate is 60% by mass or more, the adhesive force will not be too high after heating, and the adhesive sheet will be easier to peel from the adherend. If it is 80% by mass above, it is easier to peel off. If the ratio of the copolymer component derived from 2-ethylhexyl acrylate is 95% by mass or less, it is possible to prevent deformation of the base material during heating due to insufficient initial adhesive force, and the deformation of the adhesive sheet from the adherend due to the deformation. Peel off.

The type and number of copolymer components other than 2-ethylhexyl acrylate in the acrylic copolymer are not particularly limited. For example, as the second copolymer component, a functional group-containing monomer having a reactive functional group is preferable. When a crosslinking agent described later is used as the reactive functional group of the second copolymer component, it is preferably a functional group capable of reacting with the crosslinking agent. The reactive functional group is preferably, for example, at least any substituent selected from carboxyl, hydroxyl, amino, substituted amino and epoxy, more preferably at least any substituent from carboxyl and hydroxyl, even more preferably carboxyl.

Examples of the monomer having a carboxyl group (carboxyl group-containing monomer) include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Among carboxyl group-containing monomers, acrylic acid is preferred from the viewpoint of reactivity and copolymerizability. A carboxyl group-containing monomer may be used individually or in combination of 2 or more types.

Examples of monomers having a hydroxyl group (hydroxyl-containing monomers) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, Hydroxyalkyl (meth)acrylates, such as 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, etc. Among the hydroxyl group-containing monomers, 2-hydroxyethyl (meth)acrylate is preferable from the viewpoint of the reactivity of the hydroxyl group and copolymerizability. A hydroxyl group-containing monomer may be used individually or in combination of 2 or more types. In addition, "(meth)acryl" in this specification is an expression used when showing both "acryl" and "methacryl", and the same applies to other similar terms.

As an acrylate which has an epoxy group, a glycidyl acrylate, a glycidyl methacrylate, etc. are mentioned, for example.

Examples of other copolymer components in the acrylic copolymer include alkyl (meth)acrylates having 2 to 20 carbon atoms in the alkyl group. Examples of the alkyl (meth)acrylate include: ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, (meth)acrylate base) n-hexyl acrylate, 2-ethylhexyl methacrylate, isooctyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, (meth) Myristyl acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, etc. Among these alkyl (meth)acrylates, from the viewpoint of further improving the adhesiveness, (meth)acrylates having 2 to 4 alkyl carbon atoms are preferable, and n-butyl (meth)acrylate is more preferable. ester. Alkyl (meth)acrylates may be used alone or in combination of two or more.

As other copolymer components in the acrylic copolymer, for example, those derived from (meth)acrylates containing alkoxyalkyl groups, (meth)acrylates having aliphatic rings, (meth)acrylates having aromatic rings, base) acrylate, non-crosslinkable acrylamide, non-crosslinkable tertiary amino group-containing (meth)acrylate, vinyl acetate and styrene at least one monomer copolymer component.

Examples of (meth)acrylates containing an alkoxyalkyl group include methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, esters and ethoxyethyl (meth)acrylate.

As (meth)acrylate which has an aliphatic ring, cyclohexyl (meth)acrylate is mentioned, for example.

As (meth)acrylate which has an aromatic ring, phenyl (meth)acrylate is mentioned, for example.

Examples of non-crosslinkable acrylamide include acrylamide and methacrylamide.

Examples of non-crosslinkable (meth)acrylates having tertiary amino groups include (N,N-dimethylamino)ethyl (meth)acrylate and (N,N-dimethylamino)ethyl (meth)acrylate. Dimethylamino) propyl ester.

As other copolymer components in the acrylic copolymer, copolymer components derived from monomers having rings containing nitrogen atoms are also preferred from the viewpoint of increasing the polarity of the adhesive and improving the adhesiveness and adhesive force. .

Examples of monomers having a ring containing a nitrogen atom include: N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpiperidone, N-vinylpiperazine, N-vinyl Pyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinylmorpholine, N-vinylcaprolactam, N-(meth)acryloylmorpholine, etc. Among them, N-(meth)acryloylmorpholine is preferable.

These monomers may be used alone or in combination of two or more.

In the present embodiment, the second copolymer component is preferably a carboxyl group-containing monomer or a hydroxyl group-containing monomer, more preferably acrylic acid. In the case where the acrylic copolymer contains a copolymer component derived from 2-ethylhexyl acrylate and a copolymer component derived from acrylic acid, the mass of the copolymer component derived from acrylic acid is divided by the total mass of the acrylic copolymer. The proportion thereof is preferably 1% by mass or less, and more preferably 0.1% by mass or more and 0.5% by mass or less. When the ratio of acrylic acid is 1 mass % or less, when a crosslinking agent is contained in an adhesive composition, the crosslinking of an acrylic copolymer can be prevented from progressing too quickly.

The acrylic copolymer may contain two or more types of copolymer components derived from functional group-containing monomers. For example, the acrylic copolymer can be a terpolymer. When the acrylic copolymer is a ternary copolymer, it is preferably an acrylic copolymer obtained by copolymerizing 2-ethylhexyl acrylate, a carboxyl group-containing monomer and a hydroxyl group-containing monomer, and the carboxyl group-containing monomer is preferably Acrylic acid, the hydroxyl-containing monomer is preferably 2-hydroxyethyl acrylate. Preferably, the proportion of the copolymer component derived from 2-ethylhexyl acrylate in the acrylic copolymer is 80% by mass to 95% by mass, the mass proportion of the copolymer component derived from acrylic acid is 1% by mass or less, and the remainder It is a copolymer component derived from 2-hydroxyethyl acrylate.

The weight average molecular weight (Mw) of the acrylic copolymer is preferably not less than 300,000 and not more than 2 million, more preferably not less than 600,000 and not more than 1.5 million, still more preferably not less than 800,000 and not more than 1.2 million. If the weight-average molecular weight Mw of the acrylic copolymer is 300,000 or more, it can be peeled off without leaving adhesive residue on the adherend. If the weight average molecular weight Mw of an acrylic copolymer is 2 million or less, it can stick to an adherend reliably.

The weight-average molecular weight Mw of the acrylic copolymer is a value measured by gel permeation chromatography (Gel Permeation Chromatography; GPC) and converted into standard styrene.

The acrylic copolymer can be produced by a conventionally known method using the above-mentioned various raw material monomers.

The copolymerization form of the acrylic copolymer is not particularly limited, and may be any of a block copolymer, a random copolymer, or a graft copolymer.

In the present embodiment, the content of the acrylic copolymer in the adhesive composition is preferably 40% by mass to 90% by mass, more preferably 50% by mass to 90% by mass.

In the present embodiment, the adhesion aid preferably contains a rubber-like material having a reactive group as a main component. Residue can be reduced when the adhesive composition includes a reactive adhesion aid. The content of the adhesion assistant in the adhesive composition is preferably 3% by mass to 50% by mass, more preferably 5% by mass to 30% by mass. When the content of the adhesion assistant in the adhesive composition is 3% by mass or less, adhesive residue may be generated, and if it exceeds 50% by mass, the adhesive force may be lowered.

In this specification, containing a rubber-like material having a reactive group as a main component means that the mass of the rubber-like material having a reactive group accounts for more than 50% by mass of the total mass of the adhesion aid. In this embodiment, the proportion of the rubber-like material having a reactive group in the adhesion assistant is preferably greater than 50% by mass, more preferably 80% by mass or more. The adhesion aid is preferably substantially made of a rubber-like material having reactive groups.

The reactive group is preferably one or more functional groups selected from hydroxyl group, isocyanate group, amino group, oxiranyl group, acid anhydride group, alkoxy group, acryloyl group and methacryloyl group, preferably hydroxyl group. The reactive group contained in the rubber-like material may be one type, or two or more types. The rubber-like material having hydroxyl groups may further have the above-mentioned reactive groups. In addition, the number of reactive groups may be one or two or more in one molecule constituting the rubber-like material.

The rubber-based material is not particularly limited, but polybutadiene-based resins and hydrogenated polybutadiene-based resins are preferred, and hydrogenated polybutadiene-based resins are more preferred.

Examples of polybutadiene-based resins include resins having 1,4-repeating units, resins having 1,2-repeating units, and resins having both 1,4-repeating units and 1,2-repeating units . The hydrogenated product of the polybutadiene-based resin of the present embodiment also includes the hydrogenated product of a resin having these repeating units.

The polybutadiene-based resin and the hydrogenated polybutadiene-based resin preferably have reactive groups at both terminals. The reactive groups at both terminals may be the same or different. The reactive groups at both ends are preferably one or more functional groups selected from hydroxyl, isocyanate, amino, oxiranyl, anhydride, alkoxy, acryloyl, and methacryloyl groups, preferably hydroxyl. In polybutadiene-based resins and hydrogenated polybutadiene-based resins, both terminals are more preferably hydroxyl groups.

The pressure-sensitive adhesive composition of the present embodiment preferably contains a cross-linked product obtained by cross-linking a composition containing a cross-linking agent in addition to the above-mentioned acrylic copolymer and the adhesion assistant. In addition, the solid content of the pressure-sensitive adhesive composition is preferably composed of a cross-linked product obtained by cross-linking the aforementioned acrylic copolymer, adhesion assistant, and cross-linking agent substantially as described above. The term “essentially” here means that the solid content of the adhesive composition consists only of the crosslinked product, except for a small amount of impurities inevitably mixed into the adhesive.

In this embodiment, examples of crosslinking agents include isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, metal chelate crosslinking agents, and amine crosslinking agents. And amino resin crosslinking agent, etc. These crosslinking agents may be used alone or in combination of two or more.

In this embodiment, from the viewpoint of improving the heat resistance and adhesive force of the adhesive composition, among these crosslinking agents, a crosslinking agent mainly composed of a compound having an isocyanate group (isocyanate crosslinking agent) is preferable. joint agent). Examples of isocyanate crosslinking agents include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, Benzene-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, bicyclic Polyisocyanate compounds such as hexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, and lysine isocyanate.

In addition, the polyisocyanate compound may be a trimethylolpropane adduct-type modified product of the above-mentioned compound, a biuret-type modified product obtained by reacting with water, or a isocyanate-type modified product containing an isocyanate ring. things.

In this specification, a crosslinking agent mainly composed of a compound having an isocyanate group means that the mass of the compound having an isocyanate group accounts for 50% by mass or more of the total mass of components constituting the crosslinking agent.

In this embodiment, the content of the crosslinking agent in the adhesive composition is preferably 0.1 to 20 parts by mass, more preferably 1 to 15 parts by mass, relative to 100 parts by mass of the acrylic copolymer. Below, it is more preferable that it is 5 mass parts or more and 10 mass parts or less. If the content of the crosslinking agent in the adhesive composition is within such a range, the adhesiveness of the layer (adhesive layer) comprising the adhesive composition and the adherend (such as a substrate) can be improved, Thereby, the aging time for stabilizing the adhesive properties after the adhesive sheet is produced can be shortened.

In the present embodiment, the isocyanate-based crosslinking agent is more preferably a compound having an isocyanuric acid ring (modified isocyanuric acid compound) from the viewpoint of heat resistance of the adhesive composition. It is preferable to mix|blend the compound which has an isocyanuric acid ring by 0.7 equivalent or more and 1.5 equivalent or less with respect to the hydroxyl equivalent of an acrylic-type copolymer. When the compounding quantity of the compound which has an isocyanuric acid ring is 0.7 equivalent or more, the adhesive force after heating will not become high too much, it will be easy to peel off an adhesive sheet, and residual adhesive can be reduced. When the compounding quantity of the compound which has an isocyanuric acid ring is 1.5 equivalents or less, it can prevent that an initial stage adhesive force falls too much, or it can prevent that sticking property falls.

When the adhesive composition in this embodiment contains a crosslinking agent, it is preferable that the adhesive composition further contains a crosslinking accelerator. The crosslinking accelerator is preferably appropriately selected and used according to the type of crosslinking agent and the like. For example, when the adhesive composition contains a polyisocyanate compound as a crosslinking agent, it is preferable to further contain an organometallic compound-based crosslinking accelerator such as an organotin compound.

·Silicone-based adhesive composition

When the adhesive layer 12 contains a silicone-based adhesive composition, it is preferable that the silicone-based adhesive composition contains an addition-polymerizable silicone resin. In this specification, the silicone-based adhesive composition containing an addition-polymerization type silicone resin is called an addition reaction type silicone-based adhesive composition.

The addition reaction type silicone adhesive composition contains a main agent and a crosslinking agent. The addition reaction type silicone-based adhesive composition has an advantage that it can be used only by primary curing at a low temperature, and secondary curing at a high temperature is unnecessary. On the other hand, conventional peroxide-curable silicone-based adhesives require secondary curing at a high temperature of 150° C. or higher.

Therefore, the PSA sheet can be produced at relatively low temperature by using the addition reaction type silicone-based PSA composition, which is excellent in energy saving, and the PSA sheet 10 can also be produced using the substrate 11 with low heat resistance. In addition, it does not produce by-products during curing like peroxide-curable silicone-based adhesives, so there are no problems such as odor and corrosion.

Addition-reaction type silicone-based adhesive compositions generally contain: a main agent formed of a mixture of a silicone resin component and a silicone rubber component, a crosslinking agent containing a hydrosilyl group (SiH group), and, if necessary, curing catalyst.

The silicone resin component is an organopolysiloxane having a network structure obtained by hydrolyzing an organochlorosilane and an organoalkoxysilane followed by a dehydration condensation reaction.

The silicone rubber component is a diorganopolysiloxane having a linear structure.

As the organic group, in the case of the silicone resin component and the silicone rubber component, all are methyl groups, ethyl groups, propyl groups, butyl groups, phenyl groups, and the like. Some of the above-mentioned organic groups may have been substituted with vinyl, hexenyl, allyl, butenyl, pentenyl, octenyl, (meth)acryloyl, (meth)acryloylmethyl , (meth)acryloylpropyl, and unsaturated groups such as cyclohexenyl. An organic group having a vinyl group that is industrially easily available is preferable. In the addition reaction type silicone-based adhesive composition, crosslinking proceeds through the addition reaction of the unsaturated group and the hydrosilyl group to form a network structure and exhibit adhesiveness.

The number of unsaturated groups such as vinyl groups is usually not less than 0.05 and not more than 3.0 per 100 organic groups, preferably not less than 0.1 and not more than 2.5. By setting the number of unsaturated groups with respect to 100 organic groups to 0.05 or more, it is possible to prevent the reactivity with the hydrosilyl group from decreasing and hardening to be difficult, and to impart appropriate adhesive force. By setting the number of unsaturated groups to 3.0 or less per 100 organic groups, it is possible to prevent adverse effects on the adherend surface due to increased crosslinking density of the adhesive, increased adhesive force and cohesive force.

As the above-mentioned organopolysiloxane, specifically, KS-3703 (the number of vinyl groups is 0.6 per 100 methyl groups) manufactured by Shin-Etsu Chemical Co., Ltd., Dow Corning Toray Co., Ltd. ( Dow Corning Toray Co., Ltd) BY23-753 (the number of vinyl groups is 0.1 with respect to 100 methyl groups), BY24-162 (the number of vinyl groups is 1.4 with respect to 100 methyl groups), and the like. In addition, SD4560PSA, SD4570PSA, SD4580PSA, SD4584PSA, SD4585PSA, SD4587L, and SD4592PSA manufactured by Dow Corning Toray Co., Ltd. can also be used.

As mentioned above, organopolysiloxane as a silicone resin component is usually mixed with a silicone rubber component. As a silicone rubber component, Shin-Etsu Chemical Co., Ltd.'s KS-3800 (100 pieces per methyl group) , the number of vinyl groups is 7.6), BY24-162 manufactured by Dow Corning Toray Co., Ltd. (with respect to 100 methyl groups, the number of vinyl groups is 1.4), BY24-843 (without unsaturated groups) and SD -7292 (with respect to 100 methyl groups, the number of vinyl groups is 5.0), etc.

Specific examples of the above-mentioned addition reaction type silicone are described in, for example, Japanese Patent Application Laid-Open No. 10-219229.

The crosslinking agent is blended in such a way that the number of hydrogen atoms bonded to silicon atoms is usually 0.5 or more and 10 or less per one unsaturated group such as a vinyl group of the silicone resin component and the silicone rubber component. , preferably 1 or more and 2.5 or less. By setting the number of hydrogen atoms bonded to the silicon atom to be 0.5 or more, it is possible to prevent unsaturated groups such as vinyl groups from incompletely reacting with hydrosilyl groups, resulting in poor curing. By reducing the number of hydrogen atoms bonded to silicon atoms to 10 or less, it is possible to prevent the crosslinking agent from remaining unreacted and adversely affecting the surface to be adhered.

The addition reaction type silicone adhesive composition preferably contains the above-mentioned addition reaction type silicone component (the main ingredient consisting of a silicone resin component and a silicone rubber component) and a crosslinking agent. Contains curing catalyst.

This curing catalyst is used to promote the hydrosilylation reaction of the unsaturated groups in the silicone resin component and the silicone rubber component and the Si—H groups in the crosslinking agent.

As the curing catalyst, platinum-based catalysts, namely chloroplatinic acid, alcohol solution of chloroplatinic acid, reactant of chloroplatinic acid and alcohol solution, reactant of chloroplatinic acid and olefin compound, chloroplatinic acid and vinyl group-containing Reactants of siloxane compounds, platinum-olefin complexes, platinum-vinyl group-containing siloxane complexes, platinum-phosphorous complexes, and the like. Specific examples of the aforementioned curing catalyst are described in, for example, JP-A-2006-28311 and JP-A-10-147758.

More specifically, commercially available products include SRX-212 manufactured by Dow Corning Toray Co., Ltd., PL-50T manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

The content of the curing catalyst is usually not less than 5 ppm by mass and not more than 2000 ppm by mass, preferably not less than 10 ppm by mass and not more than 500 ppm by mass, based on the platinum component, based on the total amount of the silicone resin component and the silicone rubber component. By setting it at 5 mass ppm or more, it is possible to prevent the decrease in curability and reduce the crosslinking density, that is, to prevent the decrease in adhesive force and cohesive force (holding force). The stability of the adhesive layer, and it can prevent the excessive use of curing catalyst from causing adverse effects on the adhered surface.

In the addition reaction type silicone-based adhesive composition, by adding the above-mentioned components, the adhesive force can be exhibited even at normal temperature. From the viewpoint of the stability of the adhesive force, it is preferable to use the addition reaction The type silicone adhesive composition is coated on the base material 11 or the release sheet described later, and after the base material 11 and the release sheet are bonded together, heating or irradiating active energy rays promotes the formation of the silicone resin component and the silicone adhesive. The crosslinking reaction of the rubber component under the action of the crosslinking agent.

The heating temperature when accelerating the crosslinking reaction by heating is usually 60°C or more and 140°C or less, preferably 80°C or more and 130°C or less. By heating above 60°C, it is possible to prevent insufficient cross-linking of the silicone resin component and the silicone rubber component resulting in insufficient adhesive force. Deterioration and discoloration occur.

When irradiating active energy rays to promote the crosslinking reaction, active energy rays having energy quanta, that is, active light such as ultraviolet rays or electron beams can be used among electromagnetic waves or charged particle beams. When crosslinking is carried out by irradiating electron beams, a photopolymerization initiator is not required, but when crosslinking is carried out by irradiating active light such as ultraviolet rays, a photopolymerization initiator is preferably present.

There are no particular limitations on the photopolymerization initiator when irradiating ultraviolet rays, and any photopolymerization initiator can be appropriately selected and used from conventional photopolymerization initiators generally used for ultraviolet curable resins. Examples of the photopolymerization initiator include benzoins, benzophenones, acetophenones, α-hydroxyketones, α-aminoketones, α-diketones, and α-diketones. Dialkyl acetals (α-diketone dialkyl acetal), anthraquinones, thioxanthones, and other compounds.

These photopolymerization initiators may be used alone or in combination of two or more. In addition, the photopolymerization initiator is usually used in an amount of 0.01 to 30 parts by mass, preferably 0.05 The range of not less than 20 parts by mass and not more than 20 parts by mass is selected.

Crosslinking is performed by heating or irradiating active energy rays to obtain a PSA sheet with stable adhesive force.

The electron beam acceleration voltage when crosslinking is irradiated with an electron beam which is one of the active energy rays is usually 130 kV to 300 kV, preferably 150 kV to 250 kV. By irradiating an accelerating voltage of 130kV or more, it is possible to prevent insufficient crosslinking of the silicone resin component and the silicone rubber component, resulting in insufficient adhesive force. By irradiating electron beams at an accelerating voltage of 300kV or less, it is possible to prevent the adhesive layer from And base sheet deterioration, discoloration. The preferable range of the electron beam current is 1 mA or more and 100 mA or less.

The dose of electron beams to be irradiated is preferably not less than 1 Mrad and not more than 70 Mrad, more preferably not less than 2 Mrad and not more than 20 Mrad. By irradiating electron beams at a dose of 1 Mrad or more, deterioration and discoloration of the adhesive layer and the substrate sheet can be prevented, and insufficient adhesiveness due to insufficient crosslinking can be prevented. By irradiating electron beams at a dose of 70 Mrad or less, the deterioration and discoloration of the pressure-sensitive adhesive layer can be prevented from decreasing the cohesive force, thereby preventing the base sheet from deteriorating and shrinking.

The irradiation dose when irradiating ultraviolet rays can be appropriately selected, and the light dose is 100 mJ/cm ² to 500 mJ/cm ² , and the illuminance is 10 mW/cm ² to 500 mW/cm ² .

In order to prevent the reaction from being inhibited by oxygen, it is preferable to perform heating and irradiation of active energy rays in a nitrogen atmosphere.

The thickness of the adhesive layer 12 can be appropriately determined according to the application of the adhesive sheet 10 . In the present embodiment, the thickness of the pressure-sensitive adhesive layer 12 is preferably not less than 5 μm and not more than 60 μm, more preferably not less than 10 μm and not more than 50 μm. If the thickness of the adhesive layer 12 is too thin, there is a possibility that the adhesive layer 12 cannot follow the unevenness of the circuit surface of the semiconductor chip, and gaps may be generated. For example, if interlayer insulating material and sealing resin enter the gap, the electrode pads for wiring connection on the chip circuit surface may be blocked. When the thickness of the adhesive layer 12 is 5 μm or more, the adhesive layer 12 can easily follow the unevenness of the chip circuit surface, thereby preventing the occurrence of gaps. In addition, if the thickness of the adhesive layer 12 is too thick, the semiconductor chip may sink into the adhesive layer, and there may be a difference in height between the semiconductor chip portion and the resin portion sealing the semiconductor chip. If such a difference in level occurs, there is a possibility that the wiring may be disconnected during rewiring. If the thickness of the pressure-sensitive adhesive layer 12 is 60 μm or less, a difference in height is unlikely to occur.

In this embodiment, other components may be contained in the adhesive composition within the range which does not impair the effect of this invention. As other components that can be contained in the adhesive composition, for example: organic solvents, flame retardants, tackifiers, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, preservatives, anti-corrosion agents, etc. Mold agent, plasticizer, defoamer, colorant, filler, and wettability regulator, etc.

The addition reaction type silicone-based adhesive composition may contain non-reactive polyorganosiloxane such as dimethylsiloxane and dimethyldiphenylsiloxane as additives.

As a more specific example of the adhesive composition of this embodiment, the example of the following adhesive composition can be mentioned, for example, However, this invention is not limited to such an example.

As an example of the pressure-sensitive adhesive composition of this embodiment, the following pressure-sensitive adhesive composition can be mentioned, it contains acrylic copolymer, adhesion auxiliary agent and crosslinking agent, and said acrylic copolymer is at least acrylic acid An acrylic copolymer obtained by copolymerizing 2-ethylhexyl ester, a carboxyl-containing monomer, and a hydroxyl-containing monomer. The adhesion aid contains a rubber-like material with a reactive group as a main component. The crosslinking agent It is an isocyanate crosslinking agent.

As an example of the pressure-sensitive adhesive composition of this embodiment, the following pressure-sensitive adhesive composition can be mentioned, it contains acrylic copolymer, adhesion auxiliary agent and crosslinking agent, and said acrylic copolymer is at least acrylic acid Acrylic copolymer obtained by copolymerization of 2-ethylhexyl ester, carboxyl-containing monomer and hydroxyl-containing monomer. joint agent.

As an example of the pressure-sensitive adhesive composition of this embodiment, the following pressure-sensitive adhesive composition can be mentioned, it contains acrylic copolymer, adhesion auxiliary agent and crosslinking agent, and said acrylic copolymer is at least acrylic acid An acrylic copolymer obtained by copolymerization of 2-ethylhexyl ester, acrylic acid and 2-hydroxyethyl acrylate, the adhesion aid contains a rubber-like material with a reactive group as the main component, and the crosslinking agent is Isocyanate crosslinking agent.

As an example of the pressure-sensitive adhesive composition of this embodiment, the following pressure-sensitive adhesive composition can be mentioned, it contains acrylic copolymer, adhesion auxiliary agent and crosslinking agent, and said acrylic copolymer is at least acrylic acid Acrylic copolymer obtained by copolymerization of 2-ethylhexyl ester, acrylic acid and 2-hydroxyethyl acrylate, the adhesion aid is hydrogenated polybutadiene with hydroxyl groups at both ends, and the crosslinking agent is isocyanate crosslinking agent agent.

In these examples of the pressure-sensitive adhesive composition of the present embodiment, it is preferable that the ratio of the copolymer component derived from 2-ethylhexyl acrylate in the above-mentioned acrylic copolymer is 80% by mass or more and 95% by mass or less. The mass ratio of the copolymer component of a carboxyl group-containing monomer is 1% by mass or less, and the remainder is other copolymer components. As the other copolymer components, it is preferable to contain a copolymer component derived from a hydroxyl group-containing monomer.

(peeling sheet)

It does not specifically limit as release sheet RL. For example, it is preferable that the release sheet RL includes a release base material and a release agent layer formed by applying a release agent on the release base material from the viewpoint of ease of handling. In addition, the release sheet RL may be provided with a release agent layer only on one side of the release base material, or may be provided with a release agent layer on both surfaces of the release base material. Examples of the release base include paper bases, laminated papers obtained by laminating thermoplastic resins such as polyethylene on the paper bases, plastic films, and the like. Examples of the paper substrate include cellophane, coated paper, and cast coated paper. Examples of plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. Wait. Examples of release agents include olefin-based resins, rubber-based elastomers (for example, butadiene-based resins, isoprene-based resins, etc.), long-chain alkyl-based resins, alkyd-based resins, fluorine-based resins, etc. and silicone resins.

The thickness of the release sheet RL is not particularly limited. The thickness of the release sheet RL is usually not less than 20 μm and not more than 200 μm, preferably not less than 25 μm and not more than 150 μm.

The thickness of the release agent layer is not particularly limited. When forming a release agent layer by applying a solution containing a release agent, the thickness of the release agent layer is preferably not less than 0.01 μm and not more than 2.0 μm, more preferably not less than 0.03 μm and not more than 1.0 μm.

When a plastic film is used as the release base material, the thickness of the plastic film is preferably 3 μm to 50 μm, more preferably 5 μm to 40 μm.

The adhesive sheet 10 of the present embodiment preferably exhibits the following adhesive force after heating. First, the adhesive sheet 10 is pasted on the adherend (copper foil or polyimide film), heated at 100°C for 30 minutes, and then heated at 190°C for 1 hour, preferably bonded. The adhesive force of the agent layer 12 to the copper foil at room temperature and the adhesive force of the adhesive layer 12 to the polyimide film at room temperature are 0.7N/25mm or more and 2.0N/25mm or less, respectively. If the adhesive force after such heating is 0.7 N/25 mm or more, even when the substrate or the adherend is deformed by heating, it is possible to prevent the peeling of the adhesive sheet 10 from the adherend. In addition, if the adhesive strength after heating is 2.0 N/25 mm or less, the peeling force will not be too high, and it will be easy to peel the adhesive sheet 10 from the adherend.

In addition, in this specification, room temperature means the temperature of 22 degreeC or more and 24 degreeC or less. In this specification, the adhesive force is a value measured by a 180° peeling method at a tensile speed of 300 mm/min and a PSA sheet width of 25 mm.

(Manufacturing method of adhesive sheet)

The method for producing the PSA sheet 10 is not particularly limited.

For example, the pressure-sensitive adhesive sheet 10 can be manufactured through the following steps. First, an adhesive is applied on the first base material surface 11 a of the base material 11 to form a coating film. Next, this coating film is dried to form the pressure-sensitive adhesive layer 12 . Then, the release sheet RL is pasted so as to cover the pressure-sensitive adhesive layer 12 .

In addition, as another manufacturing method of the adhesive sheet 10, it can manufacture through the following process. First, the pressure-sensitive adhesive composition is applied on the release sheet RL to form a coating film. Next, the coating film is dried to form the adhesive layer 12 , and the first base material surface 11 a of the base material 11 is bonded to the adhesive layer 12 .

When applying an adhesive composition to form the adhesive layer 12, it is preferable to dilute the adhesive composition with an organic solvent, prepare a coating liquid, and use it. As an organic solvent, toluene, ethyl acetate, methyl ethyl ketone etc. are mentioned, for example. The method of applying the coating liquid is not particularly limited. Examples of coating methods include spin coating, spray coating, bar coating, knife coating, roll knife coating, roll coating, blade coating, die coating, and gravure coating. .

In order to prevent organic solvents and low boiling point components from remaining in the pressure-sensitive adhesive layer 12, it is preferable to heat and dry the coating film after coating the coating liquid on the base material 11 or the release sheet RL. Moreover, when a crosslinking agent is mix|blended with an adhesive composition, it is preferable to heat a coating film in order to advance a crosslinking reaction and improve cohesive force.

(use of adhesive sheet)

The adhesive sheet 10 is used when sealing a semiconductor element. The adhesive sheet 10 is preferably used when sealing a semiconductor element in a state of being attached to the adhesive sheet 10 without being mounted on a metal lead frame. Specifically, the adhesive sheet 10 is not used when sealing a semiconductor element mounted on a metal lead frame, but is preferably used when sealing a semiconductor element attached to the adhesive layer 12 . Examples of a method of packaging a semiconductor element without using a metal lead frame include panel-level packaging (Panel Scale Package; PSP) and wafer-level packaging (Wafer Level Package; WLP).

The pressure-sensitive adhesive sheet 10 is preferably used in a process including a process of sticking a frame member formed with a plurality of openings to the pressure-sensitive adhesive sheet 10 and sticking a semiconductor chip on the opening exposed to the frame member. The process of the adhesive layer 12, the process of covering the said semiconductor chip with a sealing resin, and the process of thermosetting the said sealing resin.

(Manufacturing method of semiconductor device)

A method of manufacturing a semiconductor device using the adhesive sheet 10 of this embodiment will be described.

2A to 2E are schematic diagrams illustrating a method of manufacturing a semiconductor device according to this embodiment.

In the manufacturing method of the semiconductor device of the present embodiment, the following steps are carried out: a step of sticking the frame member 20 formed with a plurality of openings 21 to the adhesive sheet 10 (adhesive sheet sticking step), sticking the semiconductor chip CP to the use frame. The step of forming the adhesive layer 12 exposed from the opening 21 of the member 20 (bonding step), the step of covering the semiconductor chip CP with the sealing resin 30 (sealing step), and the step of thermosetting the sealing resin 30 (Thermosetting process), and the process (peeling process) of peeling the adhesive sheet after thermosetting. If necessary, a step of sticking the reinforcement member 40 to the sealing body 50 sealed with the sealing resin 30 (reinforcement member sticking step) may be performed after the thermosetting step.

Hereinafter, each step will be described.

· Adhesive sheet sticking process

FIG. 2A is a schematic diagram showing a process for affixing the frame member 20 to the adhesive layer 12 of the adhesive sheet 10 .

The frame member 20 in this embodiment is formed in a lattice shape and has a plurality of openings 21 . The frame member 20 is preferably formed of a heat-resistant material. Examples of the material of the frame member 20 include metals such as copper and stainless steel, and heat-resistant resins such as polyimide resin and glass epoxy resin.

The opening 21 is a hole penetrating through the front and back of the frame member 20 . The shape of the opening 21 is not particularly limited as long as the semiconductor chip CP can be accommodated in the frame. The depth of the opening 21 is not particularly limited as long as it can accommodate the semiconductor chip CP.

· Bonding process

FIG. 2B is a schematic view for explaining the process of sticking the semiconductor chip CP to the adhesive layer 12 .

After the adhesive sheet 10 is attached to the frame member 20 , the adhesive layer 12 is exposed in each opening 21 according to the shape of the opening 21 . The semiconductor chip CP is attached to the adhesive layer 12 of each opening 21 . When pasting the semiconductor chip CP, its circuit surface is covered with the adhesive layer 12 .

The manufacture of the semiconductor chip CP is carried out by carrying out, for example, a back grinding process of grinding the back surface of a semiconductor wafer on which circuits are formed, and a dicing process of singulating the semiconductor wafer. In the dicing step, a semiconductor wafer is attached to an adhesive layer of a dicing sheet, and the semiconductor wafer is separated into pieces using a cutting device such as a dicing saw to obtain semiconductor chips CP (semiconductor elements).

The cutting device is not particularly limited, and known cutting devices can be used. In addition, the conditions for cleavage are not particularly limited. It should be noted that instead of cutting with a cutter, a laser cutting method, a stealth cutting method, or the like may be used.

After the dicing step, a sheet expanding step of stretching the diced sheet to widen the intervals between the plurality of semiconductor chips CP may be performed. By performing the wafer expansion step, the semiconductor chip CP can be picked up using a transport mechanism such as an opening clip. In addition, by performing the sheet expanding step, the adhesive force of the dicing sheet to the adhesive layer can be reduced, and the semiconductor chip CP can be easily picked up.

When an energy ray polymerizable compound is blended in the adhesive composition or adhesive layer of the dicing sheet, the energy ray polymerizable compound is cured by irradiating the adhesive layer with energy rays from the substrate side of the dicing sheet. After the energy ray polymerizable compound is cured, the cohesive force of the adhesive layer is improved, and the adhesive force of the adhesive layer can be reduced. Examples of energy rays include ultraviolet rays (UV) and electron beams (EB), among which ultraviolet rays are preferable. Irradiation of energy rays may be performed at any stage after bonding the semiconductor wafer and before peeling (pick-up) of the semiconductor chip. For example, energy rays may be irradiated before or after dicing, or energy rays may be irradiated after the sheet expanding process.

·Sealing process and heat curing process

FIG. 2C is a schematic view illustrating a step of sealing the semiconductor chip CP and the frame member 20 bonded on the adhesive sheet 10 .

The material of the sealing resin 30 is thermosetting resin, for example, epoxy resin etc. are mentioned. The epoxy resin used as the sealing resin 30 may contain, for example, a phenolic resin, an elastomer, an inorganic filler, a curing accelerator, and the like.

The method of covering the semiconductor chip CP and the frame member 20 with the sealing resin 30 is not particularly limited.

In this embodiment, an embodiment in which the sheet-shaped sealing resin 30 is used will be described as an example. A sheet-shaped sealing resin 30 is placed to cover the semiconductor chip CP and the frame member 20 , and the sealing resin 30 is heated and cured to form the sealing resin layer 30A. In this way, the semiconductor chip CP and the frame member 20 are embedded in the sealing resin layer 30A. When using the sheet-shaped sealing resin 30, it is preferable to seal the semiconductor chip CP and the frame member 20 by a vacuum lamination method. By this vacuum lamination method, it is possible to prevent a void from being generated between the semiconductor chip CP and the frame member 20 . The range of temperature conditions for heat curing by the vacuum lamination method is, for example, 80° C. or higher and 120° C. or lower.

In the sealing step, a laminated sheet in which the sheet-shaped sealing resin 30 is supported by a resin sheet such as polyethylene terephthalate can be used. In this case, after placing the laminated sheet so as to cover the semiconductor chip CP and the frame member 20 , the resin sheet is peeled off from the sealing resin 30 , and the sealing resin 30 is heated and cured. As such a laminated sheet, an ABF film (made by Ajinomoto Fine-Techno Co., Ltd.) is mentioned, for example.

As a method of sealing the semiconductor chip CP and the frame member 20 , a transfer method (transfer model method) can be employed. In this case, for example, the semiconductor chip CP and the frame member 20 bonded to the adhesive sheet 10 are housed inside the mold of the sealing device. A fluid resin material is injected into the mold to cure the resin material. In the case of the mold transfer method, heating and pressure are not particularly limited. As an example of normal conditions in the mold transfer method, a temperature of 150° C. or higher and a pressure of 4 MPa to 15 MPa are kept for 30 seconds or more and 300 seconds or less. Then, the pressurization was released, and it was taken out from the sealing device, left still in an oven, and kept at a temperature of 150° C. or higher for 2 hours or more and 15 hours or less. In this way, the semiconductor chip CP and the frame member 20 are sealed.

In the case of using the sheet-shaped sealing resin 30 in the above-mentioned sealing step, the first hot pressing step may be performed before the step of thermosetting the sealing resin 30 (thermosetting step). In the first heating and pressing process, the semiconductor chip CP covered with the sealing resin 30 and the adhesive sheet 10 with the frame member 20 are sandwiched from both sides by plate-like members, and carried out under the conditions of predetermined temperature, time and pressure. suppress. By performing the first heating and pressing process, the sealing resin 30 is easily filled into the gap between the semiconductor chip CP and the frame member 20 . In addition, the unevenness of the sealing resin layer 30A made of the sealing resin 30 can also be flattened by performing the heating and pressing process. As a plate-shaped member, metal plates, such as stainless steel, can be used, for example.

When the adhesive sheet 10 is peeled off after the thermosetting process, the semiconductor chip CP and the frame member 20 sealed with the sealing resin 30 can be obtained. Hereinafter, this may be referred to as a sealing body 50 .

·Strengthening the member pasting process

FIG. 2D is a schematic diagram for explaining the process of affixing the reinforcing member 40 to the sealing body 50 .

After the adhesive sheet 10 is peeled off, a rewiring step of forming a rewiring layer and a step of providing bumps are performed on the exposed circuit surface of the semiconductor chip CP. In order to improve the operability of the sealing body 50 in such a rewiring step and a step of providing protrusions, a step of affixing the reinforcing member 40 to the sealing body 50 (reinforcement member affixing step) may be performed as necessary. When implementing the reinforcement member sticking process, it is preferable to implement before peeling the adhesive sheet 10. As shown in FIG. 2D , the sealing body 50 is supported in a state sandwiched between the adhesive sheet 10 and the reinforcing member 40 .

In the present embodiment, the reinforcing member 40 includes a heat-resistant reinforcing plate 41 and a heat-resistant adhesive layer 42 .

As the reinforcing plate 41 , for example, a plate-shaped member made of heat-resistant resin such as polyimide resin and glass epoxy resin can be mentioned.

The adhesive layer 42 bonds the reinforcing plate 41 and the sealing body 50 . As the adhesive layer 42, it can select suitably according to the material of the reinforcement board 41 and 30 A of sealing resin layers. For example, when the sealing resin layer 30A contains epoxy resin and the reinforcing plate 41 contains glass epoxy resin, as the adhesive layer 42, glass fiber cloth containing thermoplastic resin is preferably used as the adhesive layer 42. thermoplastic resin, preferably bismaleimide triazine resin (BT resin).

In the reinforcing member sticking process, it is preferable to implement the following second heating and pressing process: the adhesive layer 42 is sandwiched between the sealing resin layer 30A of the sealing body 50 and the reinforcing plate 41, and then the adhesive layer 42 is inserted from the reinforcing plate 41 side and the adhesive sheet 10. The sides are clamped with plate-shaped members, and pressed under the conditions of given temperature, time and pressure. The sealing body 50 and the reinforcing member 40 are pre-fixed by the second heating and pressing process. In order to harden the adhesive layer 42 after a 2nd heat press process, it is preferable to heat the sealing body 50 and the reinforcement member 40 after fixing under conditions of predetermined temperature and time. Conditions of heat curing can be appropriately set according to the material of the adhesive layer 42 , for example, conditions of 185° C., 80 minutes, and 2.4 MPa. In the second hot pressing step, as the plate-shaped member, a metal plate such as stainless steel can be used, for example.

·Peel off process

FIG. 2E is a schematic diagram illustrating a step of peeling the adhesive sheet 10 .

In the present embodiment, when the base material 11 of the adhesive sheet 10 is bendable, the adhesive sheet 10 can be bent to be easily peeled off from the frame member 20 , the semiconductor chip CP, and the sealing resin layer 30A. The peeling angle θ is not particularly limited, but it is preferable to peel the PSA sheet 10 at a peeling angle θ of 90 degrees or more. If the peeling angle θ is 90 degrees or more, the pressure-sensitive adhesive sheet 10 can be easily peeled from the frame member 20, the semiconductor chip CP, and the sealing resin layer 30A. The peeling angle θ is preferably not less than 90 degrees and not more than 180 degrees, more preferably not less than 135 degrees and not more than 180 degrees. By peeling while bending the adhesive sheet 10 in this way, the load applied to the frame member 20, the semiconductor chip CP, and the sealing resin layer 30A can be reduced to perform peeling, thereby suppressing semiconductor damage caused by the peeling of the adhesive sheet 10. Damage to the chip CP and the sealing resin layer 30A. After the pressure-sensitive adhesive sheet 10 is peeled off, the above-mentioned rewiring process, process of providing protrusions, and the like are performed. After the pressure-sensitive adhesive sheet 10 is peeled off, before performing the rewiring process, the process of providing protrusions, etc., the above-mentioned reinforcing member sticking process may be performed as necessary.

When attaching the reinforcing member 40 , the reinforcing member 40 is peeled off from the sealing body 50 when the supporting member 40 is no longer needed after the rewiring process and the process of providing protrusions are performed.

Then, the sealing body 50 is singulated into semiconductor chips CP units (singulation process). The method of singulating the sealing body 50 is not particularly limited. For example, singulation can be performed by the same method as that used for dicing the semiconductor wafer described above. The process of singulating the sealing body 50 may be performed in a state where the sealing body 50 is attached to a dicing sheet or the like. By singulating the sealing body 50 , a semiconductor package of a semiconductor chip CP unit can be manufactured, and this semiconductor package is mounted on a printed wiring board or the like in a mounting process.

According to this embodiment, it is possible to prevent movement and positional displacement of the semiconductor chip CP in the sealing process. In the present embodiment, the adhesive layer 12 has a value of 3.0 N/chip or more obtained in a chip tensile test on silicon in an air atmosphere at 100° C., and the semiconductor chip CP is relatively difficult to peel off from the adhesive layer 12 . Therefore, in the sealing step, it is possible to prevent the semiconductor chip CP from being peeled off from the adhesive layer 12, and it is possible to prevent the semiconductor chip CP from moving or misaligned.

[Modification of Embodiment]

The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope of achieving the object of the present invention are also included in the present invention. In the following description, as long as members and the like described in the above-mentioned embodiment are the same, the same reference numerals will be assigned, and the description will be omitted or simplified.

In the above-mentioned embodiment, the form in which the pressure-sensitive adhesive layer 12 of the pressure-sensitive adhesive sheet 10 is covered with the release sheet RL was taken as an example and described, but the present invention is not limited to such a form.

In addition, the PSA sheet 10 may be provided as a single sheet or may be provided in a state where a plurality of PSA sheets 10 are laminated. In this case, for example, the adhesive layer 12 may be covered with the base material 11 of another adhesive sheet to be laminated.

In addition, the pressure-sensitive adhesive sheet 10 may be a long sheet or may be provided in a rolled state. The pressure-sensitive adhesive sheet 10 rolled into a roll can be cut into a desired size or the like after being unwound from the roll and used.

In the above-described embodiment, a case where a thermosetting resin is used as the material of the sealing resin 30 has been described as an example, but the present invention is not limited to such an embodiment. For example, the sealing resin 30 may be an energy ray curable resin that is cured by energy rays such as ultraviolet rays.

In the above-mentioned embodiment, in the description of the manufacturing method of the semiconductor device, an embodiment in which the frame member 20 is attached to the adhesive sheet 10 has been described as an example, but the present invention is not limited to such an embodiment. The adhesive sheet 10 can also be used in a semiconductor device manufacturing method for manufacturing a semiconductor element without using the frame member 20 .

Example

Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited by these Examples.

〔Evaluation method〕

The evaluation of the pressure-sensitive adhesive sheet was performed according to the method shown below.

[Chip pull test]

The values obtained in the chip pull test of the adhesive layer against silicon in an atmosphere of 100° C. were measured. Specifically, the measurement was performed according to the following steps (a) to (h).

(a) A semiconductor chip (silicon) to be measured was produced under the following conditions.

・Back grinding tape: E-8180HR (manufactured by Lintec Corporation), cutting tape: D-174A (manufactured by Lintec Corporation)

・Cutting device: "DFD651" manufactured by DISCO Corporation

· Standard cutting conditions: blade = 27HECC, 35,000rpm, cutting mode A, 50mm/sec

Chip thickness: 200μm (#2000), chip size: 6.4mm×6.4mm (6.435mm interval)

(b) As shown in FIG. 3B, double-sided adhesive tape DF (TL-6177-12-LN TEST, manufactured by Lintec Co., Ltd.) was attached to the entire surface of the bakelite board BB for lining shown in FIG. 3A, and then peeled off. Release film of double-sided tape DF.

(c) Using the adhesive layer 12 produced in Examples and Comparative Examples as a sample film, as shown in FIG. Peel off the film.

(d) As shown in FIG. 3D , semiconductor chips CP (8 pieces) were placed on the adhesive layer 12 at intervals of 2.5 cm using tweezers so that the circuit surface CPA was in contact with the adhesive layer 12 . At this time, the semiconductor chip CP is set vertically smoothly so that the corners of the semiconductor chip CP do not touch the adhesive layer 12 .

(e) The sample prepared in (d) above was subjected to vacuum lamination using a vacuum laminator under the following conditions. In addition, when performing vacuum lamination, as shown in FIG. 3E, two peeling films LF (thickness: 38 micrometers) were arrange|positioned up and down, and vacuum lamination was performed.

・Vacuum laminator: Manufactured by NISSINBO

·Temperature: 100℃

・Pressure: 100Pa, vacuum degree: not set (full suction), compression: not set (pressure difference from atmospheric pressure)

Lamination speed: high speed mode

Program: Vacuum suction for 60 seconds followed by high-speed lamination for 40 seconds

• Lamination was carried out after 1 hour after setting the temperature, with a temporary idle run before actual sample lamination.

(f) The vacuum-laminated sample in (e) above was placed on a tensile tester ("Dage 4000" manufactured by Nordson Advanced Technology), and preheated to 100°C.

(g) As shown in Fig. 3G, place the tension member PB with the double-sided tape DF2 ("A208" manufactured by Lintec Corporation) attached as shown in Fig. 3F on the semiconductor chip CP, and press it with your finger for 5 seconds . After 1 minute, the chip pull test was carried out as shown in Figure 3H under the following conditions, the displacement and force of the load cell were measured, and the peak value of the force was taken as the force (unit: N) applied to one chip (semiconductor chip CP). /chip).

·Temperature of gas environment: 100°C

·Test speed: 200μm/s

(h) Then, after removing the semiconductor chip CP from the tensile member PB, perform a chip tensile test on other semiconductor chips CP as in (g) above until the number of valid data reaches 6, and obtain the value applied to 1 chip. force. Then, the average value of the obtained effective data was taken as the value obtained in the chip pull test (unit: N/chip).

[Chip Offset Evaluation]

8,000 semiconductor chips (silicon mirror chips, chip size: 2.3 mm x 1.7 mm, Chip thickness: 0.2mm). Then, the semiconductor chip on the adhesive sheet was sealed with a sealing resin (ABF film, GX T-31, manufactured by Ajinomoto Fine-Techno) using a vacuum heat press laminator ("7024HP5" manufactured by ROHM and HAAS) . The sealing conditions are as follows.

Preheating temperature: 100°C for workbench and diaphragm

· Vacuum suction: 60 seconds

·Dynamic suppression mode: 30 seconds

·Static suppression mode: 10 seconds

Then, the semiconductor chip on the embedded adhesive sheet was observed with the naked eye and a microscope, and the presence or absence of displacement of the semiconductor chip was confirmed. The case where there is no positional deviation of the semiconductor chip is determined as "A", and the case where the positional deviation of the semiconductor chip is determined as "B". In addition, when the semiconductor chip moved 20 micrometers or more before and after embedding, it was judged as "there exists a position shift."

(Example 1)

(1) Preparation of adhesive composition

The following materials (polymer, adhesion aid, crosslinking agent, and diluent solvent) were blended and stirred sufficiently to prepare the coating adhesive solution (adhesive composition) of Example 1.

· Polymer: acrylate copolymer, 40 parts by mass (solid content)

The acrylate copolymer was prepared by copolymerizing 92.8% by mass of 2-ethylhexyl acrylate, 7.0% by mass of 2-hydroxyethyl acrylate, and 0.2% by mass of acrylic acid.

・Adhesion aid: hydrogenated polybutadiene with hydroxyl groups at both ends [manufactured by Nippon Soda Co., Ltd.; GI-1000], 5 parts by mass (solid content)

・Adhesion aid: polyetheramine derivative [manufactured by NOF Corporation; DT-203], 1.5 parts by mass (solid content)

· Crosslinking agent: aliphatic isocyanate having hexamethylene diisocyanate (isocyanate-type modified product of hexamethylene diisocyanate) [manufactured by Nippon Polyurethane Industry Co., Ltd.; Coronate HX], 3.5 parts by mass (solid Element)

• Diluting solvent: using methyl ethyl ketone, the solid content concentration of the coating binder liquid was adjusted to 30% by mass.

(2) Preparation of adhesive layer

The prepared coating adhesive solution was coated on a release film made of a 38 μm transparent polyethylene terephthalate film provided with a silicone-based release layer using a Comma Coater (registered trademark) [Lintec Manufactured by Co., Ltd.; SP-PET382150] on the peeling layer side so that the film thickness after drying was 50 μm, heating was performed at 90° C. for 90 seconds, and then heating was performed at 115° C. for 90 seconds to dry the coating film.

(3) Production of adhesive sheets

After drying the coating film of the adhesive solution for coating, the adhesive layer and the substrate were bonded together to obtain the adhesive sheet of Example 1. In addition, as a base material, a transparent polyethylene terephthalate film [manufactured by Teijin DuPont Films; PET50KFL12D, thickness 50 μm, storage modulus at 100° C. 3.1×10 ⁹ Pa] was used, and the adhesive The mixture layer is pasted on the easy-adhesive surface of the base material.

(Example 2)

The pressure-sensitive adhesive sheet of Example 2 was produced in the same manner as in Example 1 except that the adhesion assistant contained in the pressure-sensitive adhesive layer was different from that of Example 1.

The adhesion promoter used in Example 2 was hydrogenated polybutadiene [manufactured by Nippon Soda Co., Ltd.; GI-1000] with both terminal hydroxyl groups, 5 parts by mass (solid content).

(Example 3)

In Example 3, a silicone-based adhesive was used.

In Example 3, with:

Silicone adhesive A (SD4580PSA) 18 parts by mass (solid content),

Silicone adhesive B (SD4587L) 40 parts by mass (solid content),

Catalyst A (NC-25CAT) 0.3 parts by mass (solid content),

Catalyst B (CAT-SRX-212) 0.65 parts by mass (solid content), and

Primer paint (BY24-712) 5 parts by mass (solid content),

The mixture was sufficiently stirred to prepare a coating adhesive solution (adhesive composition). All materials used in the adhesive composition of Example 3 are manufactured by Dow Corning Toray.

The coating adhesive solution of Example 3 was coated on the base material, and dried so that the thickness after drying became 20 μm, thereby producing an adhesive layer. Drying conditions were 100 degreeC and 1 minute. The substrate used in Example 3 was a polyimide film [manufactured by Du Pont-Toray; KAPTON 100H, thickness 25 μm, storage modulus at 100°C: 3.1×10 ⁹ Pa]. The pressure-sensitive adhesive layer formed on the surface of the release film was bonded to the substrate to obtain the pressure-sensitive adhesive sheet of Example 3.

(Example 4)

The PSA sheet of Example 4 was produced in the same manner as in Example 2 except that the polymer contained in the PSA layer was different from that of Example 2.

The polymer used in Example 4 was prepared by copolymerizing 80.8% by mass of 2-ethylhexyl acrylate, 7% by mass of 2-hydroxyethyl acrylate, 12% by mass of 4-acryloylmorpholine, and 0.2% by mass of acrylic acid.

(comparative example 1)

The pressure-sensitive adhesive sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that the adhesion assistant contained in the pressure-sensitive adhesive layer was different from that of Example 1.

The adhesion promoter used in Comparative Example 1 was acetyl tributyl citrate [manufactured by Taoka Chemical Industry Co., Ltd.], 5 parts by mass (solid content).

Table 1 shows the evaluation results of the PSA sheets of Examples 1 to 4 and Comparative Example 1. In addition, the binders used in Examples 1-4 and Comparative Example 1 are shown in Table 1.

[Table 1]

From the results shown in Table 1, it can be confirmed that when the value obtained in the chip tensile test of the adhesive layer against silicon in an atmosphere of 100° C. is 3.0 N/chip or more (Examples 1 to 4), Chip offset can be prevented.

Claims (5)

1. a kind of bonding sheet, it is the bonding sheet used when the semiconductor element on to bonding sheet seals,

The bonding sheet possesses base material and adhesive phase, and described adhesive layer draws the chip of silicon under 100 DEG C of gaseous environment The value tried to achieve in power experiment is more than 3.0N/ chip.

2. bonding sheet according to claim 1, wherein, storage modulus of the base material at 100 DEG C is 1 × 10⁷Pa with On.

3. bonding sheet according to claim 1 or 2, wherein, described adhesive layer contains acrylic pressure-sensitive adhesive compositions Or silicone adhesive category composition.

4. bonding sheet according to claim 3, wherein, the acrylic pressure-sensitive adhesive compositions are included with acrylic acid 2- second Acrylic copolymer of the own ester of base as principal monomer.

5. bonding sheet according to claim 3, wherein, the silicone adhesive category composition, which includes addition polymerization type, to be had Machine silicones.